Struct LoopNumericSummary 

struct LoopNumericSummary {
    initial_constants: FxHashMap<Local, i128>,
    steps: FxHashMap<Local, i128>,
    guard_upper_bounds: FxHashMap<Local, NumericTerm>,
    entry_lower_bounds: FxHashMap<Local, i128>,
}

Numeric induction summary for one loop SCC.

This pass currently recognizes the small affine fragment needed by the threshold tests and by common counter loops:

• x = const before the loop.
• x = x + c, x = x - c, or the checked-overflow form tmp = x + c; x = tmp.0 inside the loop.

Fields

initial_constants: FxHashMap<Local, i128>

Constants assigned before entering this SCC.

steps: FxHashMap<Local, i128>

Per-iteration affine step for locals recognized as induction variables.

guard_upper_bounds: FxHashMap<Local, NumericTerm>

Loop guard upper bounds, for example i < len.

entry_lower_bounds: FxHashMap<Local, i128>

Lower bounds known on paths that enter this SCC, for example if len < 10 { return } gives len >= 10.

Implementations

impl LoopNumericSummary

fn new<'tcx>( tcx: TyCtxt<'tcx>, def_id: DefId, body: &Body<'tcx>, graph: &PathGraph<'_>, component: &LoopComponent, ) -> Self

Build a numeric summary for component.